Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Você pode me dizer a Data em que a Semana é menor que 13 e o Oponente dos green bay packers?
 ###Tabelas: CREATE TABLE summary_of_qualification (summary_of_qualification_id AUTO_INCREMENT PRIMARY KEY, Confederation VARCHAR, Teams started VARCHAR, Teams that have secured qualification VARCHAR, Teams that can still qualify VARCHAR, Teams that have been eliminated VARCHAR, Remaining places in finals VARCHAR, Total places in finals VARCHAR, Qualifying start date VARCHAR, Qualifying end date VARCHAR) CREATE TABLE final_league_position (final_league_position_id AUTO_INCREMENT PRIMARY KEY, Team VARCHAR, Played INT, Draw INT, Lost INT, Goals For INT, Goals Against INT, Goal Difference INT, Points INT) CREATE TABLE 2008:_atlanta_dream (2008:_atlanta_dream_id AUTO_INCREMENT PRIMARY KEY, Pick INT, Player VARCHAR, Nationality VARCHAR, New WNBA Team VARCHAR, Former WNBA Team VARCHAR, College/Country/Team VARCHAR) CREATE TABLE singles:_23_14-9 (singles:_23_14-9_id AUTO_INCREMENT PRIMARY KEY, Outcome VARCHAR, Date VARCHAR, Championship VARCHAR, Surface VARCHAR, Opponent in the final VARCHAR, Score in the final VARCHAR) CREATE TABLE schedule (schedule_id AUTO_INCREMENT PRIMARY KEY, Week INT, Date VARCHAR, Opponent VARCHAR, Result VARCHAR, Attendance INT)  
SELECT Date FROM schedule WHERE Week < 13 AND Opponent = green bay packers